Champion cyclist lance armstrong had until midnight to contest the career shattering dope charges against him by the country's highest court authority. This evening, armstrong announced he would give up his years-long fight which he called an unconstitutional witch hunt. He will be banned for cycling for life and stripped of his tour de France titles. Here is neil carlin ski. Reporter: Lance armstrong, accused of using performance enhancing drugs to work his way to the top. The stripping of his tour titles after he announced he would no longer face the charges. In a statement he writes, enough is enough. Today I turn the page. I will no longer address the issue regardless of the circumstances, adding that he is innocent and believes that the process is unfair. Does it say that he knew he couldn't win? Does it say that he knows he is guilty? There are so many questions left unanswered tonight. Reporter: So if he used drugs, how did he do it? A former teammate believed to be one of his witnesses confessed his own doping just two weeks ago. Writing, when I was racing in THE 1990s, THE RULE WRS SIR K Circumvented around anything. You saw him use epo? Yeah, I had. And I received some from him. Rath than go in the detail, yeah, I saw lance armstrong using drugs. Reporter: Armstrong always boasted he was the most tested athlete in sports history. This is his lawyer talking to "nightline" in 2010. Around 300 separate tests he has under gone and he has never had a positive test. Reporter: Armstrong retired just two years after that. The attorneys said that he faced 500 to 600 drug tests without a sing the positive. One of the earliest bits came in a hospital room in 1996 when he was recovering from cancer. A former teammate's wife testified that armstrong told doctors that he used drugs on the bike. Lance holding down the iv rattled off growth hormone, cortizone, and that was my introduction to performance enhancing drugs in the sport of cycling. Reporter: The hospital room story is a sore spot for armstrong. How could it have taken place when I have never taking performance enhancing drugs? How could that have happened. That is my point. You just don't recall -- how many times do I have to say it? I just want to make your your testimony is clear. If it can't be clearer that i have never taken drugs, than incidents like that can't happen. Reporter: They said that he used fear and coercion to make silence. They impeded on this recorded phone conversation from 2004. So many people to protect. It's sickening. Reporter: It was made by former tour winner greg lamond, a former armstrong friend and supporter. The thing that me off about it, how many people has has given false hope to. That is the most disgusting thing ever. Reporter: For some in the community cheating on the bike is outdone by good in th real world. Since his reign, so many close rivals have been caught up in doping scandals, no one can figure out that who gets the tour de France wins that armstrong may have to forfeit. I'm neil karlinski. Just ahead, he is the master

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